<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Alert学习</title>
</head>
<body>
<h2>Alert Test</h2>

<script type="text/javascript">
function showAlert(){
    alert(document.f1.t1.value);
}
</script>
<form name="f1">
    <input type="text" name="t1" value="Alert Message"><br><br>
    <input type="button" name="b1" value="Click For Alert" onclick="showAlert()"><br>
</form>
</body>
</html>
